What Are the Available Vaccines for Covid-19?

Dr. Rajesh Bhardwaj, a senior ENT specialist, talks about the COVID-19 vaccines and explains how they work, in Hindi in the below video. He answers the following questions:

a) What are the available vaccines for COVID-19? Which are the approved vaccines? 

b) How does the Moderna vaccine work? 

c) How does Covishield from AstraZeneca work? 

d) What is the Sputnik V vaccine and how does it work?

e) What is the Novavax vaccine and how does it work? 

f) Does Covaxin build immunity against the novel Coronavirus?